Drive system for circular knitting machine having a reciprocating operating mode

ABSTRACT

A power transmission to provide reciprocating heel and toe motion for a hosiery circular knitting machine, in which the knitting cylinders operate in oscillatory fashion at substantially uniform speed, with rapid acceleration and deceleration upon reversal, which has a gearing mechanism including a pair of nonround gears imparting reciprocatory motion over a connecting rod to a gear segment, the nonround gears being approximately oval and shaped to provide a substantially trapezoidally shaped speed-time of rotation curve characteristic.

limited @tatea Patent inventor Helmu! Schleclter Plochingen, Germany Appl. No. 880,225

Filed Nov. 26, 1969 Patented June 29, 1971 Assignee Fir-ma Gottlieb Eppinger Denltendorf, Germany Priority Dec. 6, 1968 Germany DRIVE SYSTEM FOR CIRCULAR KNITTING MACHINE HAVKNG A RECKFROCATING OPERATKNG MODE 3 Claims, 6 Drawing Fig.

US. Cl 66/56 int. Cl [1041) 9/00 Field of Search 66/56 1 1 ama:

[56] References Cited UNITED STATES PATENTS 2,217,022 10/1940 Lawson et 66/56X 2,582,164 1/1952 Roper... 66/56 3,427.830 2/1969 Uhlir 66/56 FORElGN PATENTS 1,111,797 3/1968 Great Britain 66/56 Primary Examiner-Ronald Feldbaum Attorney-Flynn & Frishauf ABSTRACT: A power transmission to provide reciprocating heel and toe motion for a hosiery circular knitting machine, in which the knitting cylinders operate in oscillatory fashion at substantially uniform speed, with rapid acceleration and deceleration upon reversal, which has a gearing mechanism including a pair of nonround gears imparting reciprocatory motion over a connecting rod to a gear segment, the nonround gears being approximately oval and shaped to provide a substantially trapezoidally shaped speed-time of rotation curve characteristic.

PATENTEB JUN29 l97l SHEET 1 OF 4 KNITTING MACHINE CYLINDERS HELMUT SCHLECKER Inventor ATTORNEYS PATENTED JUH29 lsn SHEET 3 CF 4 DRIVE SYSTEM FOR CIRCULAR KNITTING MACHINE HAVING A RECIPROCATING OPERATING MODE The present invention relates to reciprocatingtype heel and toe circular stocking knitting machines.

Hosiery machines of the type to which the present invention relates are generally described in Hosiery Technology" by Harry Wignall, published by National Knitted Outerwear Association, New York, N.Y., 1968, see particularly the chapter on hosiery machine drives, controls, mechanisms and sequences.

Heel and toe pockets are knitted during reciprocating motion of the knitting cylinders, whereas the tubular portions of the stocking are knitted during continuous rotation. Motive power is obtained from a shaft which always rotates in the same direction. The machine changes to reciprocating mode under an automatic control, The continuous rotary motion is interrupted by means of a clutch, and a cylinder is then driven over a gear segment which is rocked back and forth by a connecting rod. Such an arrangement, for example as disclosed in the aforementioned literature reference, has the disadvantage that the speed of the cylinder during the reciprocating mode changes, and the top speed of the cylinder can be maintained only during a comparatively short period of time. The instantaneous speed of the cylinder may be substantial at the midpoint of any reciprocatory time interval, but because of the required acceleration and deceleration, the total knitting time for heel and toe pockets may be substantial.

It has been proposed to form the reciprocatory drive other than by a gear segment driven by a connecting rod. Various cam drives have been proposed to control the operation of the cylinder (see for example British Pats. No. 1,040,021; No. 1,1 16,625). In one of these arrangements, eccentric cam discs have to be manufactured which require high precision workmanship; the gear segments have to be substantially increased in size due to unfavorable transmission ratios, and the arrangement is only operative if power transmission can be carried out without any play between the gears. To provide for adjustment, special rollers are provided which are loaded, causing substantial wear and tear on the parts.

Special coupling arrangements have also been suggested which disable the reciprocating apparatus during the normal tubular knitting mode of the machine. While wear and tear are decreased, the entire machine becomes more complicated and thus more costly.

It has also been proposed (see British Pat. No. 1,111,797) to provide a guide bolt which runs in a guide slot and to connect the connecting rod oscillating the gear segment to this guide bolt. It has been found that the angle of power application of the guide bolt in such an arrangement is undesirable, so that large forces have to be used to move the segment, causing again substantial wear and tear and constant maintenance to avoid play in the drive mechanism.

It is an object of the present invention to provide a drive mechanism which is easy to manufacture, inexpensive, and provides a substantially trapezoidally shaped curve of speed of the cylinder versus time (or angle of rotation) of the drive gear.

Briefly, in accordance with the present invention, the connecting rod driving the oscillating segment is in turn driven by a pair of nonround gears, such as elliptical gears, connected to the drive mechanism of the knitting machine, the nonroundness of one gear matching the nonroundness of the other so that the two gear wheels will remain in constant meshing engagement while providing nonuniform transmission speed to the attached connecting rod.

The invention will'be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a front view of the drive system;

FIG. 2 is a fragmentary view of the back of the driving system;

FIG. 3 is a fragmentary side view;

FIG. 4 is a fragmentary perspective view;

FIG. 5 is a schematic view of the drive system; and

FIG. 6 is a speed vs. displacement (or time) curve of the motion available at the output shaft during reciprocating mode of the apparatus.

The complete knitting machine, prime mover, and other drives will not be illustrated in detail and those skilled in the art will readily be able to fit the drive system to a stocking knitting machine, particularly in view of the aforementioned literature reference. An electric motor 1, connected to a belt 2, drives gears 3, 4, 5 and 6. Gear 6 can connect by means of a positive engagement claw clutch 7, having interengaging projections and depressions 6a, 7a, to a drive shaft 8, driving cylinder 9 of a circular knitting machine over wide angle gears 10, 11. The position of the clutch in FIG. 1 causes constant engagement of gear 6 with shaft 8, so that the cylinder 9 of the knitting machine is constantly driven in the same sense of rotation. The clutch is moved in the direction of the arrow R.

When the cylinder 9 of the knitting machine is to reciprocate to knit a heel or toe pocket, the clutch 7 is moved in the direction of arrow P. The clutch part 7b will then match into a projection 12b on a gear 12, and gear 6 will be disconnected from clutch 7, breaking the direct drive connection from gears 3, 4, 5, and 6 to the cylinder 9. Cylinder 9 is now driven by means ofa gear segment 13 (FIG. 1, FIG. 3), which meshes with pinion l2. Rocking motion of segment 13 causes pinion 12 to oscillate back and forth, thus driving cylinder 9 over right angle gears 10, 11, in a reciprocating mode.

Gear segment 13 (FIG. 3) has an attached, solid arm 14, and is journaled in a shaft 15 to enable gear segment 13 to rock back and forth. A connecting rod 17 is swingably connected at 16 to arm 14. The other end of connecting rod 17 is secured at its terminal 18 to a connecting pin 19. Connecting pin 19 is eccentrically secured to a nonround gear 20-see FIGS. 3, 4, 5. Nonround gear 20, which is generally oval, or elliptically shaped, as appears in the drawings, meshes with a further nonround gear 21, which is secured to a holding part 23, attached to a shaft 24. A round, circular gear 25 is secured to shaft 24, gear 25 meshing with gear 6 and being constantly driven thereby. Cam discs 26, 27, 28 are likewise secured to the hub 23 of shaft 24, the earns 26., 27, 28 controlling the operation of the machine. Nonround gear 20 is rotatably secured in a stub shaft 22 fixed to the machine and shown schematically only.

The speed-time (or angular position) diagram in accordance with FIG. 6 illustrates and compares the drive speeds available at the shaft 8 in accordance with conventional drives, and in accordance with the drives of the present invention. The essentially sine curve, shown in dashed form, illustrates the speed-angular position of the shaft 8. The full line graph illustrates the speed v of shaft 8 when using the drive system of the present invention. As can be seen, there is rapid acceleration, that is operating speed of the cylinder is reached quickly; the speed then remains substantially constant and rapidly drops again to zero. The top speed of the machine can be held to be below the top speed of machines of the prior art, while the average knitting speed during an entire half-cycle of reciprocatory motion can be increased. The drive in accordance with the present invention is simple to construct, does not require special camming surfaces and the gears, even the nonround gears will not be subject to unusual wear and tear.

Iclaim:

1. Circular knitting machine having reversing, reciprocating heel-toe knitting cylinder motion comprising power means (1, 2, 3, 4, 5, 6) driving said knitting machine and providing a power input;

an output shaft (9, 8, 10, 11) to drive the knitting machine cylinder; and

a drive gear providing for oscillating motion of said shaft,

said drive gear having a gear segment (13) in driving engagement (12) withisaid output shaft; a connecting rod (17)connected to oscillate said segment; and

the gear segment (13) is secured to a bellcrank (14) to rock about a fixed shaft l5); and

said connecting rod (17) is pivotally connected to the other end of said bellcrank (l4).

3. Circular knitting machine according to claim 2, wherein said connecting rod has one end mounted on the bellcrank and the other pivotally mounted on said offset position of the other (20) of said nonround gcarsi 

1. Circular knitting machine having reversing, reciprocating heel-toe knitting cylinder motion comprising power means (1, 2, 3, 4, 5, 6) driving said knitting machine and providing a power input; an output shaft (9, 8, 10, 11) to drive the knitting machine cylinder; and a drive gear providing for oscillating motion of said shaft, said drive gear having a gear segment (13) in driving engagement (12) with said output shaft; a connecting rod (17) connected to oscillate said segment; and means rocking said segment and acting on said connecting rod, said means including a pair of nonround gears (20, 21) in mutually meshing engagement, one of the gears (21) being driven (25) by said power means, and means (17, 19) interconnecting a point offset (19) from the center of the other (20) of said gears to the other end of said connecting rod (17), said nonround gears having a circumferential shape providing a generally trapezoidally shaped speed-time of rotation curve.
 2. Circular knitting machine according to claim 1, wherein the gear segment (13) is secured to a bellcrank (14) to rock about a fixed shaft (15); and said connecting rod (17) is pivotally connected to the other end of said bellcrank (14).
 3. Circular knitting machine according to claim 2, wherein said connecting rod has one end mounted on the bellcrank and the other pivotally mounted on said offset position of the other (20) of said nonround gears. 